PeptiDream Announces Second Internal Peptide Radiopharmaceutical Therapeutic Program Targeting Claudin 18.2 for the Potential Diagnosis and Treatment of Gastric Cancer

KAWASAKI, Japan--(BUSINESS WIRE)--PeptiDream Inc., a public Kanagawa, Japan-based biopharmaceutical company (President: Patrick C. Reid, hereinafter “PeptiDream”) (Tokyo:4587) today announced its second wholly-owned peptide radiopharmaceutical development candidate arising from the company’s ongoing internal peptide radiopharmaceutical discovery and development efforts. The development candidate (“PD-29875”) is a novel first-in-class highly-selective macrocyclic peptide-radioisotope (RI) conjugate against Claudin 18.2 (“CLDN18.2”), a member of the claudin family of proteins that are integral components of tight junctions found in epithelial tissues. CLDN18.2 is expressed in a variety of solid tumors, including gastric cancer, pancreatic cancer, biliary cancer, genitourinary tract cancers, and colorectal cancer, and others.

PD-29875 was discovered using PeptiDream’s proprietary PDPS technology and further optimized at PeptiDream with in vivo imaging and efficacy studies conducted at PDRadiopharma, our wholly owned subsidiary. PeptiDream has initiated IND-enabling studies of PD-29875 and intends to initially develop the therapeutic (²²⁵Ac-PD-29875) and paired diagnostic imaging agent (⁶⁴Cu-PD-29875) for the diagnosis and treatment of gastric cancer. The paired diagnostic imaging agent, which consists of the same peptide and chelator as the therapeutic, will enable us to screen and identify patients, both in clinical trials and in clinical practice, who have CLDN18.2 expressing tumors that are most likely to have a favorable clinical response from PD-29875 treatment. PeptiDream is additionally planning to initiate human Ph0 imaging studies of ⁶⁴Cu-PD-29875 in 2025, prior to the start of a Phase 1 study.

Gastric cancer is the 5^th most common cancer in and the 4^th leading cause of cancer death worldwide in 2020, representing 7% of all global cancer diagnoses, with an approximate 5-year survival rate of 32% (worldwide an estimated 1.1 million people were diagnosed with gastric cancer in 2020, with 770,000 deaths), with the incidence expected to increase to ~1.8 million new cases per year by 2040.

“We are extremely excited to announce our second internal peptide-RI clinical development candidate, PD-29875, targeting CLDN18.2 for the potential diagnosis and treatment of gastric cancer, which has a high unmet medical need.” said Patrick C. Reid PhD, President & CEO of PeptiDream. “We are preparing to potentially take PD-29875 into human imaging studies in 2025, before bringing the therapeutic and paired diagnostic into clinical development. Our PDPS platform continues to prove extremely effective in discovering novel macrocyclic peptides for the targeted delivery of conjugated radionuclide payloads to tumors, and PeptiDream is focused on creating a robust pipeline of peptide-RI conjugate therapies for the diagnosis and treatment of cancer, both internally and through our collaboration partners.”

About PeptiDream Inc.

PeptiDream Inc. (Tokyo Stock Exchange Prime Market 4587) is leading the translation of macrocyclic peptides into a whole new class of innovative medicines to address unmet medical needs and improve the quality of life of patients worldwide. In its radiopharmaceutical business, through its wholly-owned subsidiary PDRadiopharma, PeptiDream markets and sells a number of approved radiopharmaceuticals and radiodiagnostics in Japan, as well as leveraging its proprietary Peptide Discovery Platform System (PDPS) technology to discover and develop a deep pipeline of innovative targeted radiotherapeutics and radiodiagnostics, spanning both wholly-owned internal programs and globally partnered programs. In its non-radiopharmaceutical business, PeptiDream is similarly leveraging PDPS to discover and develop a broad and diverse pipeline of investigational peptide therapeutics, peptide drug conjugates (PDC) and multi-functional peptide conjugates (MPC) across an extensive global network of discovery and development partners. PeptiDream is headquartered in Kawasaki, Japan. For more information about our company, science and pipeline, please visit www.peptidream.com.